Whirl Fan

Requirements  - A thin circular tin disk.  - A pair of scissors or cutters.  - A knitting needle.  - Pliers.  - A cork.  - A candle.  - A matchbox. Procedure  - Cut teeth in the circumference of the tin disk.  - Bend the teeth a little for better effects.  - Bend the knitting needle with the pliers and push in the cork to make a handle.  - Pivot the toothed wheel on the free end of the needle.  - Now hold it above a candle flame and see how the wheel revolves. What do you think, is turning the toothed wheel ?